The custom technology is adapted from the LED lighting system that BMW uses on its autonomous vehicles. LEDs are attached to a swimmer's wrists, shoulders, hips, knees, ankles and toes using 3D-printed mounts. An underwater camera uses motion-tracking technology to break down the swimmer's movements. The same technology is used in autonomous vehicles to detect moving objects and obstacles.
This isn't the first time BMW has used their technology to help USA Swimming. The team trained for the 2012 Olympics using an older version of the autonomous tech. The current version is far more detailed and accurate than before. The new version is also far less intrusive and doesn't disrupt a swimmer's technique.
According to Bloomberg, it cost BMW about as much as a few 30-second commercials during the Olympics, or $300,000 to $600,000. The automaker has also developed a racing wheelchair for the Rio Paralympics and a two-man bobsled for the 2014 Sochi Winter Olympics.